Battery liquid level indicator



1953 G. E. MAYBACH ETAL 2,627,748

BATTERY LIQUID LEVEL INDICATOR Filed March 18, 1948 INVENTORS Gard/0 f. Ma bad? 5 A/mono H. Snyder B M v @m ATTORNEY) Patented Feb. 10, 1953 UNITED PATENT, OFFICE 2 ,627,748 i itial Snyder; Lancaster, N; -Y .,g a'ssignois to National Battery Company, St. PaulfMinn. Application-March 18, 1948, Serial has. 15,674

Y a claim.

This invention relates to improvements in st rage batteries, and more particularlyto an improved electrolyte level indicator means in'stor age batteries, wet cellsfor the like.

As is wen known, the waterccntehtoi a stora e battery electrolyte solution is constantly subject to evaporation; and there ore; must; be replaced from time to time In manyl'storage battery installatlons it'is difieult for the battery attendant to View the interpret the battery cell through the customary topfcover plate opening, either tor the purposeof inspecting the level of the battery liquid in relation to theminir'n'um' permissible level, or to observe the progre s of a refilling operation so as to avoidoverfiowin'g'cf the 'cell. Such operations are particularly dificult when the battery is set infcramped quarters with msufiicient head room thereabove, such as'is typical for example in submarineb'attery' mounting arrangements. In such cases it is; undesirabl to provide enough head room for the batteryfattendant to be enabled to maneuver himself into proper position to peer downth'rou'gh the-battery top cover opening to observe the level of the electrolyte as with the aid ofj'a flashlight "orthe like. In any case the difiiculties; attending such in spections are increased when thefattendantfis attempting to replenish thewater supply and to simultaneously watch the progress of the rising liquid 'level incidental to the refilling operation.

Numerous efforts have been previously made to devise means circumventing the disadvantages and difiiculties aforesaid, butthe results thereof have been inadequateand in 'many cases the devices have been too complicated r 'otherwise impracticable; and therefore it isan Object of the present invention to p'rovide a simplified and improved battery liquid level indicator which eliminates the difiiculties' and disadvantages bf ei r eri'art i u 7 Another object of thefirivention is to provide an improved battery liquid indicator 'wme visually signals the relation of the existing liquid level to thefdesign'ated "permissible low and high levels thereof.

Another object of theinventicn is to provide an improved-battery liquid level indicator for the'purposes described, which 'is ofut'most struc- 't'ural-simplicity.

7 Another object'of 'the'invention "is. to provide a battery liquid levelindicator which provides a visual liquid level signal of novel form.

more specific object 'oftheinv'ention is to provide "an improvedjiquiddevel inaiatar for the purposes afbrsaidfwhich'. eliminates need T2 v of head room above the storage position of the battery.

Other objects and advantages of the invention will be apparent from the specification hereinafter.

In the'drawing:

Fig. 1 is a fragmentary sectional view through a battery saver plate showing a liquid level indi cater of the invention mounted thereon;

Fig. 2 is an illustration of the form or visual signal'which is provided by 'thedViCe of the irrvention; V V

Fig. 3 is a side elevation of another form of liquid level signalingldevice of the invention;

Fig. 1 is a fragmentary rear ele'vation, on an enlarged scale, of the devicedf Fig; 3; and

Fig. 5 is a fragmentaryjfront elevation, on an enlarged scale, or the" 'device 'of Figs. 34, showing thereon the form of the liquid level signal which is provided by the device.

As illustrated, the invention comprises anelongate transparent member formed of glass or transparent plastic. material or the like,v which may be conveniently provided in generally cylin drical shape for mounting "upon an 'aper'tured portion of astor'age battery to'p'cover'plate such as'is designated'at lqgih Figs. 1 and s. More specifical'ly as shiiwnin Fig. l jthe light transmittin member 'is illustrated at 12 to comprise an upper large diameter portion 14 an'd a lower smaller diameter portion IS. The portion 1-4 thereof is press-fitted Within a 'ferrule I 8 'whichi's'extern'ally threadedas indicated at 19 so, that the "unit may be conveniently mounted in screwthre'acled relation upon the battery cover plate It! in such manner that the'u'pper 'end'faceZU of the memberi2 is exposed exteriorly of the battery case whil the inner ie'nd-otthe portion {4 and the portion IE are disposed 'interiorly of the cell. Preferablyfagasket2Z'is inoiinted'under thehe'ad of the ferrule 18 toseal'th'e juncture of the indicator device and the battery cover fplate.

The extreme inner'end ofthe indicator portion 16 is conically shaped a 4 5 an 1e 'o'r 'thereabouts, as indicated'at 24, and theishoulder be"- tween the large "and-small diameter portions 144 s is also mmeauy bevelled at "a 45 angle asindic'ated at'z's. Theportions'l dlfi are longitudinally dimensionedso that'whe'n the 'in'dicator device is mounted in operative position as shown in Fig. 1 the conicalportion Zt'will'be thereby disposed at the elevation of the lowest permissible level of the battery electrolyte solutiongwhile the bevelled fp'o'r'tiqn :25 is thereby "disposedatthe el''vationoftlie*higfidiil'iidsitidn for the electrolyte liquid. Thus, whenever the battery liquid falls below the tip of the conical portion 24, any light entering the indicator device through the end face 21:: thereof will pass downwardly lengthwise of the unit and will then be reflected back from the bevelled faces 24-25 so as to illuminate the entire top face 26. If however the tip portion 24 is in wetted contact with the battery liquid this portion will not reflect light rays incident thereto, and hence the center portion of the end face will appear to be darkened as indicated at 39 in Fig. 2 while the outer marginal portion 32 of the end face will still appear to be illuminated.

Whenever the battery liquid-level rises so as to contact the bevelled shoulder portion 26 there will be no reflection of light of the type referred to hereinabove, and therefore the entire surface of the end face 2!] including the areas designated Sit-32 will appear to be blackened. Thus, it will be appreciated that the single transparent member l2 will provide easily visible indications of the relation of the battery liquid levelto both the high and low permissible levels thereof.

As illustrated in Fig. 1, a mirror 34 may be conveniently mounted upon the ferrule l8 as by means of a bracket 36 so that the mirrorwill be disposed at any suitable angle to the long axis of the member l2, and is adjustable so that an image of the liquid level visual indication at the top face 20 will be projected laterally so as to be readily visible at a position to one side of the battery and at an elevation only slightly above the top surface of the battery. In such case the type of image which is illustrated in Fig. 2 will be seen in the mirror 34, and thus it will be understood that the indicator of the. invention provides a novel and improved multiplelevel liquid checking device which is of utmost structural simplicity.

It will also be appreciated that whereas Figs. 1-2 illustrate for example only a dual level indicator, the shaft piece [2 may if desired be formed to include any other number of successively stepped portions so as to provide further progressive subdivided indications of the liquid level movement. It is also preferred in the case of the present invention to coat the tip end portion with a colored lacquer or the like, so that whenever the liquid level recedes away from contact with the tip end 24 the latter will reflect a red or otherwise colored bulls-eye into the center portion of the image which is projected through the end face 29, as indicated at in Fig. 2.

Figs. 3, 4 and 5 illustrate a modified form of the indicator device of the invention, which comprises a transparent body 40 having a reduced diameter lower end portion 42 terminating in a conical tip 44 and including a bevel shoulder 45 at the juncture between the large and small body portions. Distinguishing from the form of the invention shown in Figs. 1-2, the device of Figs. 3-5 is formed at its upper end with a 45 bevelled side portion is and a fiatted front face 56 at a position diametrically opposite the side portion :28. Thus, whenever the device of Figs. 3-5 is inserted through an apertured portion of a battery cover plate as indicated at M, the light rays returning upwardly from the reflective surfaces idit will be again reflected interiorly of the device against the surface 48 and thence through the flat'surface 59 in a direction laterally thereof. Thus, as explained hereinabove in connection with the device of Figs. 1-2 if the tip portion 44 of the device of Fig. 3 is in contact with batters A liquid, a darkened spot will appear against the face 59 as indicated at 52 (Fig. 5). Likewise, if the liquid is also in contact with the bevelled surface 46, a correspondingly larger darkened spot will substantially cover the flat surface when the latter is viewed from the front thereof.

Thus, it will be appreciated that the invention provides an extremely simple device for multiple level indicating purposes, whereby the relation of the existing battery liquid level of the permissible low and high levels thereof is readi- 1y viewable either from a position directly above the device or from a position sidewise thereof so that no substantial head room above the battery i required.

We claim:

1. Ina wet battery cell, a liquid level indicator comprising an elongate transparent member mounted to extend into the interior of the cell with one end face of the device directed outwardly of the cell, the portion of said device extending interiorly of the cell comprising progressively reduced diameter columnar sections arranged coaxially and each terminating in a bevelled portion inclined relative to the long axis of the device, and a mirror mounted adjacent the outer end portion of the device and inclined relative to the outwardly directed end face of the device.

2. In a wet battery cell, a liquid level indicator comprising an elongate transparent member mounted to extend into the interior of the cell with one end face of the device directed outwardly of the cell, the portion of said device disposed interiorly of the cell comprising progressively offset sections each terminating in a bevelled portion inclined relative to the long axis of the device, the outwardly projecting end portion of the device being bevelled at one side thereof and flatted parallel to the longitudinal axis of the device at a position diametrically opposed to the bevelled side portion.

3. A battery liquid level indicator device for mounting upon the top cover portion of a battery cell to extend vertically downwardly thereinto and into contact with the liquid within the cell, said device comprising a vertically elongate member of transparent material having a plurality of progressively reduced sectional dimension portions arranged longitudinally thereof and outlined by offset surfaces disposed parallel to the vertical axis of said member, said portions each terminating in a bevelled shoulder formation.

a. A battery liquid level indicator device for mounting upon the top cover portion of a battery cell to extend downwardly thereinto and into contact with the liquid within the cell, said device comprising an elongate member of transparent material having a plurality of progressively reduced sectional dimension portions arrranged longitudinally thereof, said portions each terminating in a light-reflective ledge formation, the outer end portion of said member being extended beyond the battery top cover and being bevelled at one side and fiatted at the diametrically opposite side thereof.

5. In a wet battery cell, a liquid level indicator device comprising a transparent member of generally columnar shape mounted to extend into the interior of the cell with one end face of the device flatted and directed outwardly of the cell, the portion of said device disposed interiorly of the cell comprising progressively reduced diameter cylindrical portions disposed in successive coaxial relationship longitudinally of the device, each of said portions being outlined by surface elements parallel to the vertical axis of symmetry of said device and terminating in an annular portion bevelled to incline relative to the long axis of the device.

6. In a wet battery cell, a liquid level indicator comprising a transparent member of generally columnar shape mounted to extend into the interior of the cell with one end face of the device directed outwardly of the cell, the portion of said device disposed interiorly of the cell comprising progressively reduced diameter sections, each of said sections terminating in a bevelled portion inclined relative to the long axis of the device,

the outwardly projecting end portion of the del vice being bevelled at one side thereof and fiatted parallel to the longitudinal axis of the device at a position diametrically opposed to the bevelled side portion.

'7. A battery liquid level indicator device for mounting upon the top cover portion of a battery cell to extend downwardly thereinto and into contact with the liquid within the cell, said device comprising a generally columnar shaped member of transparent material having a plurality of longitudinally progressively reduced sectional dimension portions arranged axially thereof, said portions each terminating in a 45 degree bevelled shoulder formation, the outer end portion of said member being extended beyond the battery top cover and being 45 degree bevelled at one side and fiatted at the diametrically opposite side thereof.

8. In a wet battery cell, a liquid level indicator comprising an elongate transparent member mounted to extend into the interior of the cell with one end face of the device directed outwardly of the cell, the portion of said device exbevelled shoulder formation, said formations being correspondingly spaced longitudinally of said member and adapted to contact successively with the battery cell liquid as the surface thereof assumes specific correspondingly spaced levels.

GERALD E. MAYBACH. ALMOND H. SNYDER.

REFERENCES CITED v The following references are of record in the iile of this patent:

UNITED sTATEs PATENTS Number Name Date 461,370 Seidensticker Oct. 13, 1891 773,154 McFerran Oct. 25, 1904 1,883,971 Kryzanowsky Oct. 25, 1932 2',3-01,460 Sauer Nov. 10, 1942 2,368,705 Du Pont et a1. Feb. 6, 1945 2,468,833 Murphy May 3, 1949 FOREIGN PATENTS Number Country Date 412,803 Great Britain July 5, 1934 

